loosening cam sprockets for timing belt job
08-11-2005, 03:55 PM
#1
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loosening cam sprockets for timing belt job
I'm about to do my timing belt and wanted to take advice i'd read on here about loosening the cam sprockets so that my timing didn't end up "slightly off".
Do you need the special tool T40011 listed in Bentley to do this or is there some other method?
Thanks!
Do you need the special tool T40011 listed in Bentley to do this or is there some other method?
Thanks!
08-11-2005, 04:04 PM
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Nearly any gear puller will work. One with three arms works well because the sprocket has
six openings and three arms will fit and pull nicely.
I'm sure a two arm puller works as well.
I'm sure a two arm puller works as well.
08-11-2005, 04:38 PM
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Can someone explain the relationship on the sprocket-to-cam conection?
I understand the principles on the loosening and balancing the stretching/slack portion of the proceedure but does someone have a pic of the cam/sprocket joint that they can show? Guess I worry about the cams "slipping" when the sprocket is loose - its fairly easy to have the head relieve the valvespring tension and a cam turn... slamming a piston with valves in the process.
I will be doing mine and just want to know what the stuff looks like before disassy. I have a cam bar and crank pin fwiw. TIA.
I will be doing mine and just want to know what the stuff looks like before disassy. I have a cam bar and crank pin fwiw. TIA.
08-11-2005, 05:30 PM
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It's a tapered fit and the torque on the screw pushes the sprocket back on the shaft and actually
<center><img src="http://pictureposter.audiworld.com/61325/right_cam_seal.jpg"></center><p>generates a very tight fit. It does seem strange that it works without a key, but . . .
Of course correct torque of the screw and making sure that the shaft and sprocket are clean and free from oil/grease are critical.
The pic shows the camshaft without the sprocket on. The shaft is cut so that the locating ear piece only goes on one way.
Of course correct torque of the screw and making sure that the shaft and sprocket are clean and free from oil/grease are critical.
The pic shows the camshaft without the sprocket on. The shaft is cut so that the locating ear piece only goes on one way.
08-11-2005, 05:48 PM
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Ah ok. So the sproket and ear/vertical locator are independently located...
would have assumed this but the pic helps my understanding a lot. Funny there are no little slots - just friction tight.
Thanks for the help! ... wondering how many cars are a degree or so off on timing on one bank or the other...
Thanks for the help! ... wondering how many cars are a degree or so off on timing on one bank or the other...
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08-11-2005, 06:40 PM
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Use a hammer. Not kidding.
A solid tap or two perpendicular to the toothed surface should do it. Just loosen the bolt slightly to keep everything together.
Key point: Don't tighten the sprockets until the tensioner has been applied and all slack is out of the belt. Not following this step is why some cars are slightly out of time.
Key point: Don't tighten the sprockets until the tensioner has been applied and all slack is out of the belt. Not following this step is why some cars are slightly out of time.
08-11-2005, 06:59 PM
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If you look at the cams when at TDC it's pretty hard for them to spin when disconnected from the
belt . . . but they can rack about 10 degrees.
The sprocket is just a press fit taper and can spin freely without tension.
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/125-2572_IMG.JPG">
There are generally two cylinders holding one open . . .
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/126-2632_IMG.JPG">
As long as the crank pin is in . . .
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/126-2634_IMG.JPG">
And the cams are at TDC, the sprockets are loose so when you tighten them all is good.
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/cam%20timing/125-2598_IMG.JPG">
Correct drivers side timing
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/cam%20timing/125-2594_IMG.JPG">
Incorrect drivers side timing
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/cam%20timing/125-2595_IMG.JPG">
The sprocket is just a press fit taper and can spin freely without tension.
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/125-2572_IMG.JPG">
There are generally two cylinders holding one open . . .
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/126-2632_IMG.JPG">
As long as the crank pin is in . . .
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/126-2634_IMG.JPG">
And the cams are at TDC, the sprockets are loose so when you tighten them all is good.
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/cam%20timing/125-2598_IMG.JPG">
Correct drivers side timing
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/cam%20timing/125-2594_IMG.JPG">
Incorrect drivers side timing
<img src="http://66.134.70.69/files/audi/KO4%20Closeups/cam%20timing/125-2595_IMG.JPG">